The case for a modern language(jeang3nie.codeberg.page)

  char *forty_two_bee = "42b";
  char *end;
  errno = 0; // remember errno?

  long i = strtol(forty_two_bee, &end, 10);

  char *one = "one";
  char *end;
  errno = 0; // remember errno?
  long i = strtol(one, &end, 10);
  if (errno != 0) {
      perror("Error parsing integer from string: ");
  } else if (i == 0 && end == one) {
      fprintf(stderr, "Error: invalid input: %s\n", one);
  } else if (i == 0 && *end != '\0') {
      f__kMeGently(with_a_chainsaw); 
  }

  errno = 0;

  long i = strtol(input, &end, 10);

  if (end == input) {
    // no digits were found
  } else if (*end != 0 && no_ignore_trailing_junk) {
    // unwanted trailing junk
  } else if ((i == LONG_MIN || i == LONG_MAX)) && errno != 0) {
    // overflow case
  } else {
    // good!
  }

  // no assignment to errno before strtol

  int i = my_strtoul(input, &end, 10);

  if (end == 0) {
    // underflow or overflow, indicated by LONG_MIN or LONG_MAX value
  } else if (end == input) {
    // no digits were found
  } else if (*end != 0 && no_ignore_trailing_junk) {
    // unwanted trailing junk, but i is good
  } else {
    // no trailing junk, value in i
  }

  #define errno (*__thread_specific_errno_location())

  char* forty_two = 42;
  int i;
  if (sscanf (forty_two, "%d", &i) != 1) {
      /* error */
  }